Which schema is checked?

The sitemaps.org 0.9 protocol used by Google and Bing. It validates that each url has an absolute loc, a well-formed lastmod, a changefreq from the allowed enum, and a priority between 0.0 and 1.0.

What lastmod formats are accepted?

The W3C datetime profile of ISO 8601: a year, year-month, full date, or a full datetime with a required timezone such as Z or plus-or-minus an offset. Invalid calendar dates like 2026-02-30 are rejected.

Does it support a sitemap index?

Yes. If the root element is sitemapindex, each sitemap entry is checked for a required absolute loc and an optional valid lastmod, just like url entries in a urlset.

What are the size limits?

A single sitemap may list up to 50,000 URLs and each loc must be 2048 characters or fewer. The validator flags files that exceed these limits so you know to split them.

Is my sitemap uploaded?

No. Parsing uses the browser's built-in XML parser and all rule checks run in JavaScript on your device. Your sitemap, including any internal URLs, never leaves your browser.

XML Sitemap Validator

An XML sitemap lists the URLs you want search engines to crawl, along with optional metadata. Search engines silently ignore entries that break the schema, so a single relative <loc>, a malformed <lastmod>, or an out-of-range <priority> can quietly drop pages from indexing. This XML sitemap validator checks your file against the sitemaps.org 0.9 schema in your browser.

How it works

The tool first parses your input with the browser’s XML parser and reports any well-formedness error. It then inspects the root element to decide whether it is a <urlset> (a URL sitemap) or a <sitemapindex> (a list of sitemaps), and applies the matching rules:

Every <url> (or <sitemap>) must contain a <loc>, and that <loc> must be an absolute http or https URL no longer than 2048 characters.
<lastmod> must be a valid W3C / ISO 8601 date or datetime; calendar-impossible dates are rejected.
<changefreq> must be one of always, hourly, daily, weekly, monthly, yearly, or never.
<priority> must be a number between 0.0 and 1.0.
A file may contain at most 50,000 entries.

Example

In the sample, the second entry has a relative <loc> of /relative-bad, a <changefreq> of often, and a <priority> of 2.0. The validator flags all three: the URL is not absolute, often is not in the changefreq enum, and a priority above 1.0 is out of range.

Notes

Passing this validator confirms your sitemap is structurally correct, not that the listed URLs return 200 or are canonical. After it reads valid, submit the sitemap in Search Console and watch the coverage report. All checks run locally, so internal or staging sitemaps stay private.